Why my PC has ceased recognizing any flash drives plug in

Good afternoon,

I'm assuming as this is a toshiba. That you are using a windows operating system, if you are on the off chance on Linux please let me know.

Dependant on the operating system there are a few ways to diagnose this issue.

I'd like you first to start by removing the flash drive and then press the "windows" key on your keyboard and type In disk management

Once this page is loaded, keep track of how many disks are listed (starting with disk 0)

With the page loaded plug back in the flash drive, do you see any new disks listed?

If so what do you see? If these disks previously had no data on them(or data you aren't afraid to lose) and the newly added disk states "waiting Inialization" go ahead and initialize it, you should then be able to use that flash drive like new.

I will eagerly wait your respond to continue assisting you.